Electro-luminescent device (ELD) displays have high durability, long lifetime, wide viewing angle, and environment-resistances. However, the ELD displays have disadvantages in low full-color luminance and high driving voltages. The development of a new blue EL phosphor material and the realization of high luminance white using the new blue EL phosphor material have recently succeeded. Thus, the low full-color luminance of the ELDs has been greatly improved, but the high driving voltage for driving the ELD displays is unsolved. A voltage for driving an alternating current (AC) driving type (AC-) thin film ELD being sold at a market, e.g., an ELD display, is within a range between 150V-250V or above the range.